Tessa's Full Power
by JMZW
Summary: I loved reading the Infernal Devices series, but I feel there was one thing Cassandra Clare did not properly cover: Tessa's Changing, it's limitations and her other abilities. In this story I wish to convey Tessa's true, intense power.
1. Blue Sparks

_Author's note: this is my first story using this website. Ignore any inaccuracies. I hope you like it. Please review, if you want more chapters._

 **Blue Sparks**

New York, 1915

Tessa's mind was a mess. It was as if a thousand of Mortmain's dreaded clockwork flies, that she so vividly remembered, were buzzing around inside her head.

She had been feeling horrible ever since her visit to the faerie realm the week before. She had gone, with Magnus of course, to seek help from the Seelie Court in stopping her nightmares of Will, still occurring years after his death, that seemed perpetual. The moment she stepped into the lake, which magically transported her to the land under the hill, she had felt something at unease inside of her.

And now as she awoke, in her suite at Hotel Dumont in New York, she felt it more severe than ever. "Magnus!" she called.

Hurriedly, Magnus entered the room, dressed in a colourful nightgown with an intricate design of entwined, thorny roses, holding a striped cup of black tea. His dark hair was a horrid tangle of curls, exiting his scalp at unnatural angles; cat's eyes, reflecting the luminescence of candelabras aligned to the walls of the room, directed fiercely at Tessa.

"Another nightmare?" he asked with concern.

"No," replied Tessa, "that feeling I've been explaining to you—it's getting worse. It's as if, when Sydney Carton—argh!" she grunted, as blue sparks erupted around her.

Magnus' slitted eyes widen with surprise. "Tessa!" he yelled, then leaned sharply towards her.

Her expression was indifferent, perhaps slightly eased if anything. Obviously, she had not seen the rich cobalt embers escape her body. "I'm okay," she murmured. "The pain in my head intensified for a moment, but it seems to have lessened significantly now."

"Tessa, you—" he stuttered, "you discharged blue energy. Do you understand what that means?"

She sat still, her eyes rigidly locked in place, then let out a terrifying scream.


	2. Newfound Ability

**Newfound Ability**

That morning at Hotel Dumont was the first of many such occurrences, in which Tessa unleashed blue sparks. Each incident was closer to the last. After several weeks, it became daily.

Tessa knew what the events meant—azure embers were a byproduct of magic. Magnus had attempted to hide it from her at first, but she had read the Shadowhunter's Codex and too many other volumes that explained occult powers for him to successfully deny the truth of what was happening.

She had only just begun to understand her immortality—that she would live for centuries, experience the deaths of countless loved ones, breaking her heart over and over again. Now, she had to cope with this. It horrified her.

Magnus was baffled. He had never thought to be seeing Tessa—Tessa, who was not an ordinary warlock, whose mother was a Shadowhunter—releasing the blue residue of magic. And why, only now, was it happening?

To make matters worse, after each outburst, Tessa felt her energy abruptly diminish. Something had to be done if she was to survive future outpourings.

Four weeks past the first morning, once she had recovered after a particularly beastly spasm, Magnus entered her chambers carrying a peculiar assortment of objects. Carefully gripped in his left hand were a vial of dark, red liquid; a long quill, but no parchment nor paper; and three round, black candles of varying lengths. In his right hand he held an iridescent, green crystal and a curved stick, carved into the shape of a hideous skull at one end. Balanced on his elbow was a wide bowl of murky water.

"By the Angel, what is this?" Tessa questioned, clearly startled. She put down the novel she had been reading and crouched up in her bed.

After quickly setting each item down on Tessa's wooden dressing table, one by one, he turned to face her alarmed countenance. "I want you to hold each of these objects," he started in a placid voice that seemed to calm her, "and attempt to use them. I will explain how, just pick one up."

"But these are warlock utensils!" she protested.

"I know," he stated tersely.

She stood up, hesitantly, and walked slowly towards the dresser. She reached out to grasp the item that looked the least freakish, then turned to face Magnus.

"Ah, with that you will need the ink." He removed the vial of red liquid she had previously suspected to be blood, from the shelf, and firmly placed it in her hand. Then he demonstrated drawing a demonic glyph on the floor with his finger.

The quill was shaking in her slender hand as she kneeled to the ground, dipped it into the vial of blood-coloured ink, and scrawled on the floor. The shaky blob did not resemble the shape of the rune from Magnus' demonstration even slightly, and it slowly faded away.

Disappointed, Magnus took the bowl of cloudy water from the tabletop, and placed it in front of her for the next test. Together, they experimented with each item. Magnus became more frustrated with each of Tessa's failures. She did not look any happier than he.

After almost an hour of fruitless efforts only one assessment remained—or three if you prefer.

Magnus held the pitch-black candles out to Tessa. "Theresa," he said, using the extended version of Christian name, "draw upon the sensation you have been experiencing, endure the pain, and focus on one of the candles," he ordered desperately.

She grasped the closet candle and stared at the top end of it. She felt something unlock inside of her, as the blue sparks appeared once again, and the wick erupted into hot, orange flames.


End file.
